From head to tail: new models and approaches in primate functional anatomy and biomechanics

BIOMECHANICS. Why the seahorse tail is square

Whereas the predominant shapes of most animal tails are cylindrical, seahorse tails are square prisms. Seahorses use their tails as flexible grasping appendages, in spite of a rigid bony armor that fully encases their bodies. We explore the mechanics of two three-dimensional-printed models that mimic either the natural (square prism) or hypothetical (cylindrical) architecture of a seahorse tail to uncover whether or not the square geometry provides any functional advantages. Our results show that the square prism is more resilient when crushed and provides a mechanism for preserving articulatory organization upon extensive bending and twisting, as compared with its cylindrical counterpart. Thus, the square architecture is better than the circular one in the context of two integrated functions: grasping ability and crushing resistance.

Pancreas anatomy and surgical procedure for pancreatectomy in rhesus monkeys

BACKGROUND

The aim of this study was to investigate the pancreas anatomy and surgical procedure for harvesting pancreas for islet isolation while performing pancreatectomy to induce diabetes in rhesus monkeys.

METHODS

The necropsy was performed in three cadaveric monkeys. Two monkeys underwent the total pancreatectomy and four underwent partial pancreatectomy (70-75%).

RESULTS

The greater omentum without ligament to transverse colon, the cystic artery arising from the proper hepatic artery and the branches supplying the paries posterior gastricus from the splenic artery were observed. For pancreatectomy, resected pancreas can be used for islet isolation. Diabetes was not induced in the monkeys undergoing partial pancreatectomy (70-75%).

CONCLUSIONS

Pancreas anatomy in rhesus monkeys is not the same as in human. Diabetes can be induced in rhesus monkeys by total but not partial pancreatectomy (70-75%). Resected pancreas can be used for islet isolation while performing pancreatectomy to induce diabetes.